物探与化探Issue(2)：211-219,9.DOI:10.11720/j.issn.1000-8918.2014.2.05
华南地球化学走廊带碎屑沉积岩W、Sn时空分布特征及其指示意义
SPATIAL-TEMPORAL DISTRIBUTION OF W AND Sn IN CLASTIC SEDIMENTARY ROCKS ALONG A TRANSECT ACROSS SOUTH CHINA AND ITS IMPLICATIONS
摘要
Abstract
South China is comprised of Yangtze and Cathaysia blocks bounded by the NEE-SWW extending Jiangshan-Shaoxing fault. In order to have a better understanding of the abundance and spatial-temporal distribution of each element in South China, the authors have conducted a geochemical investigation along a 2500 km transect in South China since 2008. 470 samples of fine-grained clastic sedimentary rocks from Middle Proterozoic to Cretaceous in age were collected from the Yangtze block to Cathaysia block at a spacing of 1 site/1~4 km. Analyses of 76 elements have provided us with an insight into the composition and distribution of major and minor ele-ments in sedimentary rocks from Middle Proterozoic to Cretaceous. All the samples are characterized by significant fractionation of LREE and HREE and negative Eu anomalies (Eu/Eu*=0.67 on average). The significant depletion of Ca, Na and Sr and the high CIW values suggest intermediate to intense chemical weathering of the source rocks. Discrimination diagrams involving La, Th, Sc, Co, and Hf indicate a multiple lithological source composed of granitic, andesitic and felsic volcanic rocks. The geochemical features show that the samples were derived from distant and large provenances, and the concentrations of tungsten and tin of the samples can provide robust estimates of the composition of their region. Along the transect, the values of W and Sn decrease from southeast to northwest and descend abruptly near the Jiangshan-Shaoxing fault. The distribution of W and Sn matches well with the characteristics of W-Sn mineral-ization in the Cathaysia Block. The Cathaysia Block has high W and Sn relative to UCC, and peak values are existent in the Middle Proterozoic -Ordovician rocks , reflecting the high background in this block , which might explain the reason for the formation of the world's largest W, Sn metallogenic province.关键词
地球化学/稀土元素/碎屑沉积岩/华南走廊带/钨/锡Key words
geochemistry/rare earth elements/clastic sedimentary rocks/South China transect/W and Sn分类
天文与地球科学引用本文复制引用
赵起超,迟清华,王学求,刘东盛,刘汉粮,周建..华南地球化学走廊带碎屑沉积岩W、Sn时空分布特征及其指示意义[J].物探与化探,2014,(2):211-219,9.基金项目
国土资源部行业专项 （）
